Which urinary characteristic is indicative of intrarenal failure?

The characteristic that is indicative of intrarenal failure is low urine osmolality. In cases of intrarenal failure, the kidneys are unable to properly concentrate urine due to damage to the renal tubules. This impairment leads to the excretion of urine that is less concentrated, which is reflected in lower urine osmolality.

When the kidneys are functioning properly, they typically reabsorb water and solutes to produce concentrated urine, leading to high urine osmolality and high specific gravity. However, in intrarenal failure, the damaged nephron units cannot perform these functions effectively, resulting in a diluted urine output.

Therefore, a low urine osmolality indicates that the kidneys are failing to concentrate urine, thereby serving as a key indicator of intrarenal failure. This understanding helps in differentiating the type of acute kidney injury and guides appropriate management strategies for patients experiencing renal issues.